Methods and systems are provided for detecting and measuring a peak value of a light pulse. One example method involves (i) receiving an analog signal comprising a pulse, (ii) differentiating the analog signal, using a differentiator, to provide a differentiated signal, (iii) detecting, using a comparator, a zero-crossing in the differentiated signal, (iv) delaying the analog signal by a delay amount, using a signal buffer, to provide a time-delayed analog signal, (v) in response to detecting the zero-crossing, causing a measurement of the time-delayed analog signal to be obtained, (vi) determining a measurement time associated with the measurement, and (vii) outputting the measurement and the measurement time. The methods and systems may be implemented for light detection and ranging (LIDAR) applications. In such applications, the measurement and measurement time may correspond to an object and a distance of the object, respectively, in an environment of a LIDAR device.
|
1. A method comprising:
receiving an analog signal comprising a pulse;
directing a first portion of the analog signal to a differentiator and a second portion of the analog signal to a signal buffer;
differentiating the first portion of the analog signal, using the differentiator, to provide a differentiated signal;
detecting, using a comparator, a zero-crossing in the differentiated signal;
delaying the second portion of the analog signal by a delay amount, using the signal buffer, to provide a time-delayed analog signal;
in response to detecting the zero-crossing, causing a measurement of the time-delayed analog signal to be obtained;
determining a measurement time associated with the measurement; and
outputting the measurement and the measurement time.
15. A non-transitory computer readable medium having stored thereon instructions executable by a computing device to cause the computing device to perform functions comprising:
receiving a measurement of an analog signal comprising a pulse, wherein a first portion of the analog signal is differentiated, by a differentiator, to provide a differentiated signal and a zero-crossing in the differentiated signal is detected, by a comparator, and a second portion of the analog signal is delayed, by a signal buffer, to provide a time-delayed analog signal and the measurement is a digital output from an analog-to-digital converter (ADC) that samples the time-delayed analog signal based on the zero-crossing detected by the comparator; and
receiving a measurement time associated with the measurement.
9. A device comprising:
an input, wherein the input is configured to receive an analog signal comprising a pulse;
a differentiator, wherein the differentiator is configured to differentiate a first portion of the analog signal to provide a differentiated signal;
a comparator, wherein the comparator is configured to detect a zero-crossing in the differentiated signal;
a signal buffer, wherein the signal buffer is configured to delay a second portion of the analog signal by a delay amount to provide a time-delayed analog signal;
an analog-to-digital converter (ADC), wherein the ADC is configured to obtain a measurement of the time-delayed analog signal based on the zero-crossing detected by the comparator; and
a time-to-digital converter (TDC), wherein the TDC is configured to determine a measurement time associated with the measurement.
2. The method of
4. The method of
providing the differentiated signal to the comparator; and
receiving from the comparator an output indicating a transition from on to off.
5. The method of
providing to a flip-flop circuit the output of the comparator indicating a transition from on to off; and
receiving from the flip-flop circuit an output that causes an analog-to-digital converter (ADC) to sample the time-delayed analog signal and provide a digital output that corresponds to the measurement.
6. The method of
providing to a flip-flop circuit the output of the comparator indicating a transition from on to off; and
receiving from the flip-flop circuit an output that causes a time-to-digital converter (TDC) to provide an output that corresponds to the measurement time.
7. The method of
8. The method of
10. The device of
11. The device of
12. The device of
13. The device of
14. The device of
16. The computer readable medium of
17. The computer readable medium of
18. The computer readable medium of
19. The computer readable medium of
|
Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Light distance and ranging (LIDAR) is an optical remote sensing technology that may be utilized to acquire information on a surrounding environment. The LIDAR device may use ultraviolet, visible, or infrared light to illuminate and acquire information on a variety of different types of objects, such as metallic and non-metallic items, geological formations, and even atmospheric elements. The acquired information may include distances and textures of objects in the surrounding environment.
In operation, a LIDAR device may be configured to illuminate the objects with light, detect light reflected from the objects, and determine information on the objects based on the reflected light. In such an implementation, a distance of an object may be determined based on a time between when a light pulse for illuminating the object is transmitted and when a corresponding reflected light pulse is received at the LIDAR device. Further, a reflective property (or texture) of the object may be determined based on an amplitude of the reflected light pulse.
In one aspect, a method is provided. The method may involve receiving an analog signal comprising a pulse, differentiating the analog signal, using a differentiator, to provide a differentiated signal, detecting, using a comparator, a zero-crossing in the differentiated signal, delaying the analog signal by a delay amount, using a signal buffer, to provide a time-delayed analog signal, in response to detecting the zero-crossing, causing a measurement of the time-delayed analog signal to be obtained, determining a measurement time associated with the measurement, and outputting the measurement and the measurement time.
In another aspect, a device is provided. The device may include an input configured to receive an analog signal comprising a pulse, a differentiator configured to differentiate the analog signal to provide a differentiated signal, a comparator configured to detect a zero-crossing in the differentiated signal, a signal buffer configured to delay the analog signal by a delay amount to provide a time-delayed analog signal, an analog-to-digital converter (ADC) configured to obtain a measurement of the time-delayed analog signal based on the zero-crossing detected by the comparator, and a time-to-digital converter (TDC) configured to determine a measurement time associated with the measurement.
In a further aspect, a non-transitory computer-readable medium having instructions stored thereon is provided. The instructions may be executable by a computing device to cause the computing device to perform functions including receiving a measurement of an analog signal comprising a pulse. A first portion of the analog signal is differentiated, by a differentiator, to provide a differentiated signal. A zero-crossing in the differentiated signal is detected, by a comparator. A second portion of the analog signal is delayed, by a signal buffer, to provide a time-delayed analog signal. The measurement is a digital output from an analog-to-digital converter (ADC) that samples the time-delayed analog signal based on the zero-crossing detected by the comparator. The functions further include receiving a measurement time associated with the measurement.
These as well as other aspects, advantages, and alternatives, will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings.
In the following detailed description, reference is made to the accompanying figures, which form a part thereof. In the figures, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, figures, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are contemplated herein.
A LIDAR device may be configured to illuminate an object in a surrounding environment with a light pulse, detect a corresponding light pulse reflected from the object, and determine information on the object based on the detection of the reflected light. The detection of the reflected light pulse may be implemented in different ways. In one example, the LIDAR device may be configured to measure a signal generated from the received reflected light pulse. For instance, the signal may be sampled by an analog-to-digital converter (ADC) to generate a digital signal representative of a magnitude of the pulse when sampled.
In the first example light pulse sampling 100, sampling of the input signal may be configured to occur periodically at times t1, t2, t3, t4, and so on. As shown in
In such a case, the LIDAR device may have missed the pulse 102 because the sampling rate is too low.
In a LIDAR application, the magnitude of a detected light pulse may be indicative of a reflectivity and accordingly, a texture, or material of the object reflecting the light that is received. As such, while in this example, information from the sample taken at t4 may be sufficient for roughly estimating a distance of the object, the information may not be sufficient for determining the texture or material of the object. Accordingly, the sampling rate of the LIDAR device may be further increased to improve a resolution of the information acquired based on the sampled data. For instance, an even higher sampling rate may result in sampling the pulse 102 at, or closer to the peak of the pulse 102, thereby providing a more accurate determination of what the object might be. In these cases, however, the costs of providing higher sampling, both in the form of monetary costs, such as that of faster, higher quality ADCs, and in the form of increased power consumption for the increased sampling rates, may become prohibitive and/or impractical.
An example method may detect a peak of the light pulse and measure the light pulse at the peak.
Method 200 may include one or more operations, functions, or actions as illustrated by one or more of blocks 202-216. Although the blocks are illustrated in a sequential order, these blocks may also be performed in parallel, and/or in a different order than those described herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and/or removed based upon the desired implementation. In addition, for the method 400 and other processes and methods disclosed herein, the flowchart shows functionality and operation of one possible implementation of present embodiments. In this regard, each block may represent a module, a segment, or a portion of program code, which includes one or more instructions executable by a processor or electronic circuit for implementing specific logical functions or steps in the process.
The program code may be stored on a storage medium, or any type of computer readable medium such as, for example, a storage device including a disk or hard drive. The computer readable medium may include non-transitory computer readable medium, for example, such as computer-readable media that stores data for short periods of time like register memory, processor cache and Random Access Memory (RAM). The computer readable medium may also include non-transitory media, such as secondary or persistent long term storage, like read only memory (ROM), optical or magnetic disks, compact-disc read only memory (CD-ROM), for example. The computer readable media may also be any other volatile or non-volatile storage systems. The computer readable medium may be considered a computer readable storage medium, for example, or a tangible storage device.
At block 202, the method 200 may involve receiving an analog signal. In one example, the analog signal may be the input signal having a pulse, such as the pulse 102 of
Rather than periodically sampling the analog signal to detect a received light pulse, as previously discussed, a peak of the pulse 302 may be detected, and the detection of the peak may be based upon to cause a measurement of the pulse 302 to be taken at the peak of the pulse 302. In other words, a measurement of the pulse 302 at the peak of the pulse 302 may be taken when the peak of the pulse 302 had been detected.
At block 204, the method 200 may involve differentiating the analog signal, using a differentiator, to provide a differentiated signal. Prior to the pulse 302 arriving at the reference position 304, the differentiated signal, absent any noise in the analog signal, may remain at zero. As the pulse 302 begins to arrive at the reference position 304, the differentiated signal may become positive as the pulse value at the reference position 304 increases.
In other words, the peak of the pulse 302 may be detected by detecting a zero-crossing in the differentiated signal. Accordingly, at block 206, the method 200 may involve detecting a zero-crossing in the differentiated signal. Detection of a zero-crossing in a signal may be implemented using a number of different electronic circuits. In one example, a comparator may be configured to detect the zero-crossing in the differentiated signal. For instance, the comparator may be configured to receive a changing signal, and provide an output of 1 (“on”) if the signal is increasing or 0 (“off”) if the signal is decreasing. In other words, the differentiated signal from the differentiator may be provided to the comparator, and an output from the comparator may be received indicating whether the differentiated signal is increasing or decreasing. As such, a zero-crossing in the differentiated signal may be detected when the output of the comparator switches. Particular to the present, a switch in the output of the comparator from on to off, indicating a zero-crossing in the differentiated signal from positive to negative, may be based upon to determine the presence of the peak in the pulse 302.
As indicated previously, a measurement of the pulse may be triggered in response to the detection of the peak of the pulse 302. In one example, a flip-flop (or latch) circuit configured to output an “on” signal when an input circuit to the flip-flop circuit transitions from on to off, and output an “off” signal otherwise may be provided. As such, the output of the comparator may be provided to the flip-flop circuit such that an output of the flip-flop circuit switches “on” when the output of the comparator transitions from on to off. In other words, the output of the flip-flop circuit switches on when the peak of the pulse 302 is detected. Accordingly, the output of the flip-flop circuit may be used to cause the analog signal to be measured.
As discussed, detection of the peak of the pulse 302 involves detecting a zero-crossing indicative of values of the pulse 302 at reference position 304 transitioning from increasing to decreasing. As such, by the time the peak of the pulse 302 has been detected, the peak of the pulse 302 has already travelled past the reference position 304. Further, the signal processing of the differentiator, comparator, and flip-flop circuit adds additional time between when the peak of the pulse 302 reaches the reference position 304 and when the output of the flip-flop circuit triggers a measurement of the analog signal.
In such a case, a delayed portion of the analog input signal may be generated and provided for measuring. At block 208, the method 200 may involve delaying the analog signal by a delay amount to provide a time-delayed analog signal. In one example, the analog input signal may be split such that a first portion of the split analog signal is provided for peak detection through the differentiator, comparator, and flip-flop circuit discussed above, and a second portion of the split analog signal may be delayed and provided for measurement. In other words, the first portion of the analog signal received by the LIDAR device may be directed to the differentiator of the LIDAR device, while the second portion of the analog signal may be directed to a signal buffer, for example, to provide a time-delayed analog signal.
In one example, the delay amount by which the analog signal is delayed may depend on operating times of the differentiator, the comparator, and the flip-flop circuit. In some cases the delay amount may further take into account other hardware and/or operational delays within the LIDAR device. Ultimately, the goal of the delay amount is such that a point in the time-delayed analog signal corresponds to an output of the flip-flop circuit resulting from the same point in the original analog signal. In one instance, the delay amount may be determined during a research and design stage of the LIDAR device based on specifications of the differentiator, the comparator, and the flip-flop circuits used in the device. In another instance, the delay amount may be further calibrated for the LIDAR device during manufacturing to account for variations in the circuit components. In an illustrative example, the delay amount may be in the range of 3 to 4 nanoseconds.
At block 210, the method 200 may involve causing a measurement of the time-delayed analog signal to be obtained. As indicated above in connection to block 206, the measurement of the time-delayed analog signal may be in response to a detection of the peak of the pulse in the analog signal. As such, a measurement may be made at a peak of a pulse in the time-delayed signal corresponding to the detected peak of the pulse in the analog signal. In one example, an ADC may be configured to receive the time-delayed analog signal, receive outputs from the flip-flop circuit, and sample the time-delayed analog signal in response to outputs of the flip-flop circuit. As indicated previously, the ADC may be configured to sample the time-delayed analog signal when the output of the flip-flop circuit is “on.” Upon sampling the time-delayed analog signal, the ADC may provide a digital output corresponding to a measurement of the time-delayed analog signal. For instance, the ADC may provide a digital output representative of a magnitude or peak value of the pulse.
As discussed previously in reference to LIDAR devices, a distance of an object may be determined based on a time between when a light pulse for illuminating the object is generated and when a corresponding reflected light pulse is detected at the LIDAR device. As such, a time associated with a detected light pulse may be measured to determine a distance of the object reflecting the detected light pulse. Accordingly, at block 212, the method 200 may involve determining a measurement time associated with the measurement of the time-delayed analog signal in response to the “on” output of the flip-flop circuit.
In one example, the measurement time may be determined by a time-to-digital converter (TDC). In one case, the TDC may also receive outputs from the flip-flop circuit, and accordingly, may provide an output corresponding to the measurement time in response to the “on” output of the flip-flop circuit. As such, the measurement time from the TDC may correspond to when the peak of the pulse occurs in the analog signal, relative to a reference time. In one example, the reference time may be a time when a generated light pulse corresponding to the detected light pulse reflected from the object in the surrounding environment is provided by the LIDAR device. As such, the measurement time may be based upon to determine a distance of the object in the surrounding environment. In one case, the measurement time also may be adjusted to account for time delays due to the differentiator, the comparator, and the flip-flop circuit.
Upon determining the measurement of the time-delayed analog signal at block 210, and the measurement time associated with the measurement at block 212, information associated with the object in the surrounding environment may be determined. At block 214, the method 200 may involve outputting the measurement and the measurement time. At block 216, the measurement and the measurement time may be provided to a computing device within, or coupled to the LIDAR device for further processing to determine the information, such as the distance and/or texture of the object in the surrounding environment from which the detected light was reflected.
As shown, the light pulse detection device 400 includes an input 402, a signal splitter 404, a differentiator 406, a comparator 408, a flip-flop/latch 410, a TDC 416, a delay 412, an ADC 414, and digital outputs 418 and 420. In one example, the input 402 may be configured to receive an analog input signal representative of reflected light, as previously discussed. In this example, the input 402 may be coupled to the output of a photo-detector configured to receive the reflected light. In some cases, the input 402 may be coupled to the output of the photo-detector via a signal processor where the output of the photo-detector is filtered and amplified to provide to the input 402 a cleaner input signal with improved signal-to-noise ratio.
The signal splitter 404 is coupled to the input 402 and is configured to direct a first portion of the input signal to the differentiator 406 and a second portion of the input signal to the delay 412. The signal splitter 404 could be, for example, a passive circuit component, an active circuit component, or a combination of passive and active circuit components that can output two substantially identical portions of the analog signal received at input 402.
The differentiator 406 may then receive the first portion of the analog signal from the splitter 402 and accordingly provide a differentiated signal. In one example, the differentiator 406 may be a circuit including a high input impedance operational amplifier coupled to an input capacitor and a feedback resistor. In this example, the current flowing through the capacitor may be proportional to the derivative of the voltage across the capacitor, and a voltage output proportional to the derivative of the voltage may be generated from the current flowing through the feedback resistor. In another example, the differentiator 406 may be a passive RC circuit including a capacitor in series with the input and an output resistor. Other circuit designs for the differentiator 406 may also be possible.
The comparator 408 may then receive the differentiated signal from the differentiator 406 and provide an output indicating whether the differentiated signal is positive (input signal is increasing) or negative (input signal is decreasing). In one example, the comparator 408 may include an operational amplifier having one input coupled to ground and the other input coupled to the differentiator 406 to receive the differentiated signal. In operation, the comparator 408 may then provide an output of 1 (“on”) if the differentiated signal is greater than 0, at ground, or 0 (“off”) if the differentiated signal is less than 0. Accordingly, a transition from 1 to 0 or from 0 to 1 in the output of the comparator 408 may indicate a zero-crossing in the differentiated signal. Other circuit designs for the comparator 408 may also be possible.
The output of the comparator 408 may then be provided to the flip-flop/latch 410, which may be one of a number of different flip-flop or latch circuits, such as a set-and-reset latch, a gated latch, or a D flip-flop. In one example, the flip-flop/latch 410 may be configured to store a previous input (or state) and provide an output based both the previous input and a current input. As applicable to the pulse detection device 400, the flip-flop/latch 410 may be configured to provide a 1 (“on”) output if consecutive inputs to the flip-flop/latch 410 transitioned from 1 to 0, and provide a 0 (“off”) output otherwise. As such, the flip-flop/latch 410 may output a 1 when a zero-crossing, indicating a peak of a pulse in the analog input signal is detected. Other circuit configurations for the flip-flop/latch 410 may also be possible.
As discussed in connection to the method 200 and shown in
In addition to receiving the output from the flip-flop/latch 410, the ADC 414 as shown in
The ADC 414 may be configured to then take a measurement of the time-delayed analog signal in response to the output of 1 from the flip-flop/latch 410 and provide a digital output 420. Given that the delay 412 provides a time-delayed version of the input analog signal such that a point in the time-delayed analog signal corresponds to an output of the flip-flop/latch 410 resulting from the same point in the original analog signal, the measurement of the time-delayed analog signal will correspond to a magnitude or value at the peak of the detected pulse. In one example, the ADC 414 may include an array of comparators configured to sample the time-delayed analog signal and output an incremented, digital representation of the value of the time-delayed analog signal. Other implementations of the ADC 414 may also be possible.
As shown in
While the examples discussed above in connection to method 200 shown in
For example, a time associated with the measurement of the pulse peak value may not be needed. This may be the case when another component in the LIDAR device is configured to determine distances of objects in the surrounding environment. As such, block 212, and TDC 416 may be removed from method 200 and pulse detection device 400, respectively. Similarly, in another case, if another component in the LIDAR device is configured to determine the pulse peak value, block 210 and ADC 414 may be removed from method 200 and pulse detection device 400, respectively. In this case, the delay 412 may also be removed. Other variations are also be possible
As indicated above, in some embodiments, the disclosed methods may be implemented by computer program instructions encoded on a non-transitory computer-readable storage media in a machine-readable format, or on other non-transitory media or articles of manufacture.
In one embodiment, the example computer program product 500 may be provided using a signal bearing medium 502. The signal bearing medium 502 may include one or more programming instructions 504 that, when executed by one or more processors may provide functionality or portions of the functionality described with respect to
The one or more programming instructions 504 may be, for example, computer executable and/or logic implemented instructions. In some examples, a processing unit such as one that may be a part of the light pulse detection device in
The non-transitory computer readable medium could also be distributed among multiple data storage elements, which could be remotely located from each other. The computing device that executes some or all of the stored instructions could be a computing device such as any of those described above. Alternatively, the computing device that executes some or all of the stored instructions could be another computing device, such as a server.
While various aspects and embodiments have been disclosed herein, it should be understood that the embodiments are example embodiments and are described in connection to just some of many possible applications. Accordingly, it should also be understood that other aspects and embodiments are also possible. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
Levandowski, Anthony, Droz, Pierre-yves
Patent | Priority | Assignee | Title |
10003168, | Oct 18 2017 | LUMINAR TECHNOLOGIES, INC | Fiber laser with free-space components |
10007001, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Active short-wave infrared four-dimensional camera |
10012732, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system |
10061019, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Diffractive optical element in a lidar system to correct for backscan |
10088559, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Controlling pulse timing to compensate for motor dynamics |
10094925, | Mar 31 2017 | LUMINAR TECHNOLOGIES, INC | Multispectral lidar system |
10114111, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Method for dynamically controlling laser power |
10121813, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Optical detector having a bandpass filter in a lidar system |
10139478, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Time varying gain in an optical detector operating in a lidar system |
10191155, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Optical resolution in front of a vehicle |
10209359, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Adaptive pulse rate in a lidar system |
10211592, | Oct 18 2017 | LUMINAR TECHNOLOGIES, INC | Fiber laser with free-space components |
10211593, | Oct 18 2017 | LUMINAR TECHNOLOGIES, INC | Optical amplifier with multi-wavelength pumping |
10241198, | Mar 30 2017 | LUMINAR TECHNOLOGIES, INC | Lidar receiver calibration |
10254388, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Dynamically varying laser output in a vehicle in view of weather conditions |
10254762, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Compensating for the vibration of the vehicle |
10267898, | Mar 22 2017 | LUMINAR TECHNOLOGIES, INC | Scan patterns for lidar systems |
10267899, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Pulse timing based on angle of view |
10267918, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Lidar detector having a plurality of time to digital converters integrated onto a detector chip |
10295668, | Mar 30 2017 | LUMINAR TECHNOLOGIES, INC | Reducing the number of false detections in a lidar system |
10310058, | Nov 22 2017 | LUMINAR TECHNOLOGIES, INC | Concurrent scan of multiple pixels in a lidar system equipped with a polygon mirror |
10324170, | Apr 05 2018 | LUMINAR TECHNOLOGIES, INC | Multi-beam lidar system with polygon mirror |
10324185, | Nov 22 2017 | LUMINAR TECHNOLOGIES, INC | Reducing audio noise in a lidar scanner with a polygon mirror |
10340651, | Aug 21 2018 | LUMINAR TECHNOLOGIES, INC | Lidar system with optical trigger |
10340653, | Mar 16 2017 | Luminar Technologies, Inc. | Solid-state laser for lidar system |
10348051, | May 18 2018 | LUMINAR TECHNOLOGIES, INC | Fiber-optic amplifier |
10401481, | Mar 30 2017 | LUMINAR TECHNOLOGIES, INC | Non-uniform beam power distribution for a laser operating in a vehicle |
10418776, | Mar 16 2017 | LUMINAR TECHNOLOGIES, INC | Solid-state laser for lidar system |
10451716, | Nov 22 2017 | LUMINAR TECHNOLOGIES, INC | Monitoring rotation of a mirror in a lidar system |
10488496, | Nov 05 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system with improved scanning speed for high-resolution depth mapping |
10502831, | Nov 22 2017 | LUMINAR TECHNOLOGIES, INC | Scan sensors on the exterior surfaces of a vehicle |
10520602, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Pulsed laser for lidar system |
10545240, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | LIDAR transmitter and detector system using pulse encoding to reduce range ambiguity |
10551501, | Aug 09 2018 | LUMINAR TECHNOLOGIES, INC | Dual-mode lidar system |
10557939, | Oct 19 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system with improved signal-to-noise ratio in the presence of solar background noise |
10557940, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system |
10571567, | Nov 22 2017 | LUMINAR TECHNOLOGIES, INC | Low profile lidar scanner with polygon mirror |
10578720, | Apr 05 2018 | LUMINAR TECHNOLOGIES, INC | Lidar system with a polygon mirror and a noise-reducing feature |
10591600, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system with distributed laser and multiple sensor heads |
10591601, | Jul 10 2018 | LUMINAR TECHNOLOGIES, INC | Camera-gated lidar system |
10627495, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Time varying gain in an optical detector operating in a lidar system |
10627516, | Jul 19 2018 | LUMINAR TECHNOLOGIES, INC | Adjustable pulse characteristics for ground detection in lidar systems |
10641874, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Sizing the field of view of a detector to improve operation of a lidar system |
10663564, | Mar 30 2017 | LUMINAR TECHNOLOGIES, INC | Cross-talk mitigation using wavelength switching |
10663585, | Nov 22 2017 | LUMINAR TECHNOLOGIES, INC | Manufacturing a balanced polygon mirror |
10663595, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Synchronized multiple sensor head system for a vehicle |
10677897, | Apr 14 2017 | LUMINAR TECHNOLOGIES, INC | Combining lidar and camera data |
10684360, | Mar 30 2017 | LUMINAR TECHNOLOGIES, INC | Protecting detector in a lidar system using off-axis illumination |
10720748, | Oct 18 2017 | LUMINAR TECHNOLOGIES, INC | Amplifier assembly with semiconductor optical amplifier |
10732281, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Lidar detector system having range walk compensation |
10969488, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Dynamically scanning a field of regard using a limited number of output beams |
10976417, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Using detectors with different gains in a lidar system |
10983213, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Non-uniform separation of detector array elements in a lidar system |
11002853, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Ultrasonic vibrations on a window in a lidar system |
11022688, | Mar 31 2017 | LUMINAR TECHNOLOGIES, INC | Multi-eye lidar system |
11022689, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Pulsed laser for lidar system |
11029406, | Apr 06 2018 | LUMINAR TECHNOLOGIES, INC | Lidar system with AlInAsSb avalanche photodiode |
11119198, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Increasing operational safety of a lidar system |
11181622, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Method for controlling peak and average power through laser receiver |
11204413, | Apr 14 2017 | LUMINAR TECHNOLOGIES, INC | Combining lidar and camera data |
11346925, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Method for dynamically controlling laser power |
11378666, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Sizing the field of view of a detector to improve operation of a lidar system |
11415677, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Pulse timing based on angle of view |
11486984, | Dec 26 2018 | GUANGZHOU WOYA LAIDELING TECHNOLOGY CO , LTD | Three-dimensional light detection and ranging system using hybrid TDC and ADC receiver |
11506764, | Dec 26 2018 | GUANGZHOU WOYA LAIDELING TECHNOLOGY CO , LTD | System and methods for ranging operations using multiple signals |
11513198, | Jan 04 2019 | Waymo LLC | LIDAR pulse elongation |
11567200, | Nov 22 2017 | LUMINAR TECHNOLOGIES, INC | Lidar system with polygon mirror |
11609329, | Jul 10 2018 | LUMINAR TECHNOLOGIES, INC | Camera-gated lidar system |
11686821, | Mar 22 2017 | LUMINAR TECHNOLOGIES, INC | Scan patterns for lidar systems |
11774561, | Feb 08 2019 | LUMINAR TECHNOLOGIES, INC | Amplifier input protection circuits |
11802946, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Method for dynamically controlling laser power |
11846707, | Mar 29 2017 | LUMINAR TECHNOLOGIES, INC | Ultrasonic vibrations on a window in a lidar system |
11874401, | Mar 28 2017 | LUMINAR TECHNOLOGIES, INC | Adjusting receiver characteristics in view of weather conditions |
11892567, | Jan 04 2019 | Waymo LLC | LIDAR pulse elongation |
11933895, | Nov 22 2017 | LUMINAR TECHNOLOGIES, INC | Lidar system with polygon mirror |
9804264, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system with distributed laser and multiple sensor heads |
9810775, | Mar 16 2017 | LUMINAR TECHNOLOGIES, INC | Q-switched laser for LIDAR system |
9810786, | Mar 16 2017 | LUMINAR TECHNOLOGIES, INC | Optical parametric oscillator for lidar system |
9812838, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Pulsed laser for lidar system |
9823353, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system |
9841495, | Nov 05 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system with improved scanning speed for high-resolution depth mapping |
9857468, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system |
9869754, | Mar 22 2017 | LUMINAR TECHNOLOGIES, INC | Scan patterns for lidar systems |
9874635, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system |
9897687, | Nov 05 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system with improved scanning speed for high-resolution depth mapping |
9905992, | Mar 16 2017 | LUMINAR TECHNOLOGIES, INC | Self-Raman laser for lidar system |
9958545, | Nov 30 2015 | LUMINAR TECHNOLOGIES, INC | Lidar system |
9989629, | Mar 30 2017 | LUMINAR TECHNOLOGIES, INC | Cross-talk mitigation using wavelength switching |
Patent | Priority | Assignee | Title |
3790277, | |||
4700301, | Mar 12 1981 | Method of automatically steering agricultural type vehicles | |
4709195, | Sep 12 1986 | SPECTRA-PHYSICS, INC , | Bar code scanner with DC brushless motor |
5006721, | Mar 23 1990 | PERCEPTRON, INC | Lidar scanning system |
5202742, | Oct 03 1990 | Aisin Seiki Kabushiki Kaisha | Laser radar for a vehicle lateral guidance system |
5367162, | Jun 23 1993 | Leco Corporation | Integrating transient recorder apparatus for time array detection in time-of-flight mass spectrometry |
5982214, | Aug 06 1996 | LG Semicon Co., Ltd. | Variable delay circuit |
7089114, | Jul 03 2003 | Vehicle collision avoidance system and method | |
7187452, | Feb 09 2001 | First Data Corporation | Lidar system and method |
7248342, | Feb 14 2003 | United States of America as represented by the Administrator of the National Aeronautics and Space Administration | Three-dimension imaging lidar |
7255275, | Sep 12 2005 | Symbol Technologies, LLC | Laser power control arrangements in electro-optical readers |
7969558, | Jul 13 2006 | VELODYNE LIDAR USA, INC | High definition lidar system |
20020000466, | |||
20070183008, | |||
20110141453, | |||
20120069321, | |||
20120170024, | |||
20120170029, | |||
20120269304, |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Mar 04 2013 | Google Inc. | (assignment on the face of the patent) | / | |||
Mar 18 2013 | DROZ, PIERRE-YVES | Google Inc | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 032436 | /0453 | |
Mar 10 2014 | LEVANDOWSKI, ANTHONY | Google Inc | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 032436 | /0453 | |
Mar 21 2017 | Google Inc | WAYMO HOLDING INC | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 042084 | /0741 | |
Mar 22 2017 | WAYMO HOLDING INC | Waymo LLC | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 042085 | /0001 | |
Sep 29 2017 | Google Inc | GOOGLE LLC | CHANGE OF NAME SEE DOCUMENT FOR DETAILS | 044144 | /0001 | |
Sep 29 2017 | Google Inc | GOOGLE LLC | CORRECTIVE ASSIGNMENT TO CORRECT THE CORRECTIVE BY NULLIFICATION TO CORRECT INCORRECTLY RECORDED APPLICATION NUMBERS PREVIOUSLY RECORDED ON REEL 044144 FRAME 0001 ASSIGNOR S HEREBY CONFIRMS THE CHANGE OF NAME | 047894 | /0508 | |
Sep 29 2017 | Google Inc | GOOGLE LLC | CORRECTIVE ASSIGNMENT TO CORRECT THE THE REMOVAL OF THE INCORRECTLY RECORDED APPLICATION NUMBERS 14 149802 AND 15 419313 PREVIOUSLY RECORDED AT REEL: 44144 FRAME: 1 ASSIGNOR S HEREBY CONFIRMS THE CHANGE OF NAME | 068092 | /0502 | |
Oct 01 2019 | Waymo LLC | Waymo LLC | SUBMISSION TO CORRECT AN ERROR MADE IN A PREVIOUSLY RECORDED DOCUMENT THAT ERRONEOUSLY AFFECTS THE IDENTIFIED APPLICATIONS | 050978 | /0359 |
Date | Maintenance Fee Events |
Oct 02 2019 | M1551: Payment of Maintenance Fee, 4th Year, Large Entity. |
Nov 27 2023 | REM: Maintenance Fee Reminder Mailed. |
May 13 2024 | EXP: Patent Expired for Failure to Pay Maintenance Fees. |
Date | Maintenance Schedule |
Apr 05 2019 | 4 years fee payment window open |
Oct 05 2019 | 6 months grace period start (w surcharge) |
Apr 05 2020 | patent expiry (for year 4) |
Apr 05 2022 | 2 years to revive unintentionally abandoned end. (for year 4) |
Apr 05 2023 | 8 years fee payment window open |
Oct 05 2023 | 6 months grace period start (w surcharge) |
Apr 05 2024 | patent expiry (for year 8) |
Apr 05 2026 | 2 years to revive unintentionally abandoned end. (for year 8) |
Apr 05 2027 | 12 years fee payment window open |
Oct 05 2027 | 6 months grace period start (w surcharge) |
Apr 05 2028 | patent expiry (for year 12) |
Apr 05 2030 | 2 years to revive unintentionally abandoned end. (for year 12) |